The Debunker: Was Pompeii Buried in Lava When Mount Vesuvius Erupted?

by Ken Jennings

We usually think of volcanic eruptions as sudden and dramatic events, but that's not always the case. The Hawaiian volcano of Kilauea, for example, has been erupting continuously since January 3, 1983, covering 48 square miles of the state's "big island" with new lava. In honor of the thirty-fifth anniversary of Earth's longest-erupting volcano, Jeopardy!'s Ken Jennings will be here all month providing explosive corrections to a lot of popular misinformation about volcanoes. The results might just rock your world.

The Debunker: Was Pompeii Buried in Lava When Mount Vesuvius Erupted?

Mount Vesuvius, a stratovolcano on the Gulf of Naples, erupted violently in the year 79 AD, destroying the resort towns of Pompeii and Herculaneum. "Many besought the aid of the gods, but still more imagined there were no gods left, and that the universe was plunged into eternal darkness for evermore," wrote the Roman author Pliny the Younger, who witnessed the eruption and then the death of his own famous uncle, Pliny the Elder, in the subsequent cataclysm.

The Debunker

Poor Herculaneum is largely forgotten today (except by tourists enjoying the mosaics—it was by far the wealthier town) but the destruction of Pompeii has been a popular theme for artists, writers, and filmmakers ever since the town was first excavated in the 18th century. Many of these works emphasize the glowing, fiery lava flows cascading down the slopes of Vesuvius and, in the Hollywood versions, even fireballs streaking from heaven and exploding on impact, a thing that did not happen at Pompeii.

As a result, it's commonly believed that hot lava flows wiped out Pompeii, leaving bodies buried in rock that were later displayed for tourists in plaster-cast form. The great classical historian Mary Beard wrote of these bodies, "They are so eloquently trapped in that no man's land between the living and the dead, captured at the very moment when they lost their struggle against the fumes and lava." But Beard is wrong on two counts. Pompeii was never buried in lava; lava generally flows so slowly that it can be outpaced at a brisk walk. Rather, Pompeii was buried in pyroclastic flow, a wave of relatively cool ash and rock rushing downhill at speeds up to 150 miles per hour. And a 2010 study of the victims of Pompeii revealed that their poses don't suggest suffocation by volcanic fumes either, as had long been believed. It looks more like they were killed instantly by a flash of extreme heat. But it's hard to make a Hollywood disaster movie about a bunch of Roman vacationgoers who abruptly bake to death and then get buried under fifteen feet of ash.

Quick Quiz: Pompey the Great was a general who served in Rome's "First Triumvirate" alongside what famous man, who was also his father-in-law?

Ken Jennings is the author of eleven books, most recently his Junior Genius Guides, Because I Said So!, and Maphead. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at ken-jennings.com or on Twitter as @KenJennings.